Together with recent progress in the digital audio technology, associated technologies for converting analog audio signals into digital signals and recording them on a tape are developed. Since a significantly wide exclusive frequency band is required to convert analog signals into digital signals, a magnetic head for signal recording or reproduction on a tape must have a wide contact area per unit time. In this respect, it is indispensable to replace a conventional fixed-head arrangement by a rotary head arrangement. Therefore, various tape recorders including a rotary head have been proposed to meet the requirement.
Such a tape recorder or other magnetic recording apparatus including a rotary head requires a loading mechanism which moves right and left loaing blocks back and forth to wind the tape on the rotary head. The tape loading mechanism is configured to rotate right and left loading gears with the energy of a loading motor and move the right and left loading blocks back and forth in response to motions of loading arms effected by rotations of the loading gears. Positional relationships between respective members in th tape loading mechanism are such that the right and left loading gears directly engage each other, and respective loading blocks are located at opposite outer positions of the loading gears.
However, if the loading arms are located at opposite outer positions of the gears, they require large moving spaces, respectively, and often hit or contact reel bases during back and forth movements of the loading blocks. If the loading arms are mounted in a crossing fashion, they require moving spaces above the reel bases, and this invites an increase in height of the mechanism. Thus both arrangements cause a dimensional increase of the mechanism.
On the other hand, simultaneously with back and forth movements of the loading blocks effected by the loading arms, a pinch roller arm has to be driven to move a pinch roller back and forth. If the tape loading mechanism is used to drive the pinch roller arm, it is necessary to regulate relative motion timings between the pinch roller and the loading blocks, i.e. between the pinch roller arm and the loading arm. In this respect, a prior art mechanism includes a timing regulating arrangement using a transmission means which establishes engagement between a cam groove provided in a drive gear connected to a loading motor and a cam plate connected to the loading gears. However, this invites a complicated transmission arrangement and increases the scale of the mechanism.
Such a dimensional increase of the mechanism is against a strong demand of scale reduction of a tape recorder particularly for use in a car.